JPH02288093A - Dimming rack - Google Patents

Abstract

PURPOSE: To accomplish convenience and simplification of structure, handling, and usage by stacking a plurality of circuit boards in the vertical direction and arranging them inside a casing body in order with an electric connecting member. CONSTITUTION: A dimming rack 10 is constructed of a casing body 12 and a plurality of dimming circuit boards 14 stacked vertically in the casing body 12. In the front face of the casing body 12, a door 16, whose area is 50% or less of the opening area of the casing body 12, is arranged, so that it is convenient for use in a narrow space. The dimming circuit board 14 is housed precisely in the casing body 12 via a circuit board holder 58 by means of a female fitting joint and a male fitting joint. Inside the casing body 12, a wiring bus bar 30, a signal distribution card 32, and a non-polar terminal board 50 are respectively stacked vertically so as to be arranged in order. A plurality of dimming racks can be used while connected mutually in the lateral direction if necessary, when an upper knockdown panel 17, which is adjacent to the racks parallelly, is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an enclosure for mounting electronic equipment, particularly for mounting a plurality of dimmer circuit boards for supplying power to lighting devices such as incandescent lamps. The present invention relates to a housing having a unique structure with compartments, often called a dimming rack or dimmer rack.

[Prior Art] Light control devices using light control racks are already used in many lighting control applications such as in buildings, theaters, and television studio sets. Such racks are equipped with mechanical means for mounting each of the plurality of dimmer circuit boards and electrical means for electrically connecting them and inputting power and control signals. Thereby, each dimmer circuit board can be used to control the power supplied to a particular group or row of lighting devices, such as incandescent lamps. The dimmer circuit board, in response to input and power control signals sent to the dimmer circuit board through the dimmer rack circuitry, directs a regulated amount of power back through the dimmer rack electrical circuitry. It is sent to the lighting device being operated.

Most conventional dimming racks have consisted of an aluminum framework and chassis that house a predetermined number of plug-in dimmer circuit boards, ranging from 6 to 200 or more, and one or more plug-in control circuit boards. Input/output connections for receiving input and control signals and for transmitting power therefrom to the operating lighting equipment are provided on the rear panels of such framework and chassis members.

These conventional dimming racks have structural and operational problems, including the provision of removable shelves and partitions, which are a means of attaching individual dimming circuit boards to the dimming rack. was there. When making wiring connections or rewiring to the dimmer circuit board, the user must remove and install the required mechanical components before wiring can be made or the rack is ready for use. No. In many cases, the arrangement and mechanical construction of the racks make this a difficult, inconvenient, and time-consuming task.

The physical placement of the various electrical connections in conventional dimming racks is also problematic. Generally, the power distribution positions of input/output and control signals are taken into consideration, but the position of electrically non-polar terminals is often postponed, making them difficult to handle and inaccessible. This creates a problem in that wiring is troublesome and difficult.

Since the power demand of a light control device is large, it is common to supply power to a lighting load in three phases. Conventional light control devices generally have a rack structure in which a group of light control circuit boards connected to each phase of input power are arranged horizontally. When increasing the number of lighting loads operated by a light control device and increasing the number of light control racks used side by side, electrical connections between the racks become a major problem. Connecting one rack to the next requires finding a suitable location for the busbars. Generally, they were located at the back or bottom of the dimming rack. Separate phases are then connected to the busbars by cabling, and in some cases cabling is also used to make electrical connections between racks, making this method difficult and expensive. Also, problems arose when isolating the phases from each other.

The conventional light control rack has a limited current interrupting capacity due to its characteristics. In typical conventional equipment, 10,000 amperes was the upper limit of the maximum rating of the dimming rack. Therefore, if more capability was required, an amplifier trap type fuse was added. However, in conventional rack constructions, amplifier traps are typically located in inconvenient and awkward locations.

In the structure of the dimming rack, it is desirable to provide the dimming control device with a member for a backup mode of operation. Such modes of operation require some circuitry to be provided to ensure that one of the dimmer circuit boards receives power and turns on the desired light even if the control board or control circuit board electronics fail. It is. For this reason, in many cases, a fixed number of diodes were hard-wired to a specific dimming circuit board. The disadvantage of such an arrangement is that it lacks flexibility and can only bypass a very limited number of very specific circuits. It was not possible for the user to choose whether or not to bypass any circuit board. The fixed wiring of diodes means that they are usually inaccessible or difficult to change or rearrange.

[Problems to be Solved by the Invention] It is an object of the present invention to provide a light control rack that is convenient and simple in construction, handling, and use.

That is, both power and signaling hardware can be easily accessed. Separate vertical separation of power phases makes rack-to-rack coupling convenient, safe, and easy.

The emergency switch is separated from the control electronics for easy access and reprogramming.

One emergency switch shall be provided on each dimmer circuit board.

[Means for Solving the Problems] The rack configuration according to the present invention arranges all the dimming circuit boards in one vertical row, thereby separating the plurality of horizontally arranged circuit boards that are characteristic of the conventional technology. This eliminates the need for bulkheads and other hardware normally used to separate buildings. Additionally, the present invention provides a circuit board placement pedestal comprising horizontal shelves on which each circuit board is mounted with precision female and male mating joints. Six pieces are integrally molded on the shelf,
These engage grooves formed on the outside of the dimmer circuit board exterior to precisely position each circuit board on the shelf and connect it electrically to the input/output and control signal distribution busbars. It guides you through connecting and disconnecting.

The hardware that sends power and control signals to and from the dimmer circuit board is located on either side of the installed enclosure and extends in parallel, either in the form of a power distribution bus or in the form of a terminal block connection. ing.

One side of the housing is provided with members for connecting input power and control signals to the dimmer circuit board. In addition, on the other side, an output power terminal board that can connect the dimmer circuit board to the power output terminal is provided adjacent to and parallel to the non-polar terminal board.
Wiring from the dimming rack to the lighting load and back from there is greatly simplified and can be done quickly without the need to remove or install dividers or previously installed hardware.

[Operations] As mentioned above, the dimming rack of the present invention has the circuit boards mounted and loaded in a single vertical arrangement, while the three busbars corresponding to each of the three phases of input power are also loaded. They are arranged vertically one over the other with sequential intervals. This allows racks to be interconnected directly adjacent to each other through the side walls of the racks, eliminating the need for cumbersome cabling and external busbar equipment at the bottom of the racks.
Allows for interconnect cross-wiring and other wiring and busbar placement without intersecting or passing through adjacent phase hardware at all.

In a presently preferred embodiment, a dimming rack for supporting a plurality of dimmer circuit boards provided by the present invention comprises a vertically elongated housing and a shelf for mounting a plurality of dimmer circuit boards. It has a plurality of base holders. The first electrical connection member is incorporated into the first side of the housing for the transmission of control signals, and the second electrical connection member is adjacent to the first electrical connection member for the transmission of input power controlled by the dimming circuit board. and is incorporated into the first side of the housing.

A third electrical connection member is incorporated on the opposite side of the first side for receiving output power from the dimmer circuit board and transmitting the power to a corresponding lighting load at a location remote from the dimmer rack. . The first, second and third electrical connection members are adapted to electrically connect each of the dimming circuit boards to the plug-in base.

The dimming rack according to the invention represents a very significant improvement over conventional dimming racks. The dimmer circuit board can be quickly, accurately and consistently installed and removed, and is configured to accommodate the rough tolerances found in conventional configurations. Eliminates the hassle of positioning found in heavy and expensive connection terminals. and foundation support hardware is no longer required. Placing the circuit boards in a single vertical array results in a highly efficient and compact structure, which greatly reduces the space required for dimming racks. By arranging the circuit boards vertically, the power phases can also be separated, and if a large number of racks are required, the racks can be directly connected horizontally with busbars. The shelf is an injection molded product integrally provided with a convex piece. The circuit board is accurately fitted into the convex piece that engages with the fitting groove formed on the exterior of the circuit board, and the circuit board is fitted with a rational and elaborate busbar provided for output power, non-polar connection members, and signal distribution. Can be connected and disconnected by sliding movement. All connection terminals are chamfered for ease of use and can be inserted easily.

By locating a power disconnect switch on either dimmer circuit board in a location convenient for the user, a virtually fully operational bypass line is possible.

[Examples] In order to clarify various features of the present invention, the following description will be given based on the accompanying drawings.

A dimming rack according to the invention is shown in FIGS. 1A, 1B and 1C. As shown, the light control rack 10 includes a housing 12 and a plurality of light control circuit boards 14 vertically stacked inside the housing.

The door 16 closes a portion of the front opening of the light control rack,
It has the ability to keep circuit boards in a rack. Preferably, the width of the door is 5 times the width of the front opening of the dimming rack.
Keep it below 0%.

The light control rack according to the present invention may have various shapes without departing from the gist of the present invention, and may include a housing with a shelf on which all the circuit boards are mounted in one vertical row. It has become a feature. If more dimming circuit boards are required than can be accommodated in a single vertical array, the unique arrangement of the dimming rack structure according to the present invention allows the individual electrical phase separations of one rack to be connected to each other and other corresponding The electrical contacts can be interconnected horizontally on either side of the rack with another dimming rack installed adjacent to it.

A door lock 18 is provided on the top of the enclosure and also on the bottom of the rack if required. Above the base plate 24 at the bottom of the casing, one or two control circuit boards 20 containing electronic equipment for controlling the operation of the light control rack and a light control circuit board 14 mounted inside the rack are arranged. There is. In a normal arrangement, the exhaust fan 26 is provided at the top of the dimming rack;
The airflow generated by this fan flows straight upwards within the dimming rack. A circular grill 28 is provided on the outside of the fan at the top of the rack. A knockout panel 17 is provided on the side panel of each rack, so that the racks can be easily connected to the busbar when necessary.

Figures 2A, 2B and 2C show the dimming rack 10 of the present invention in further detail. FIG. 2A is a front view of the rack 10 with the dimmer circuit board removed and the door 16 fully open. A power distribution bus 30 and a signal distribution card 32 are provided on the left side of the rack when facing the rack. A non-polar bus bar 35 and a load connection terminal 37 are provided on the right side.

A ground connection terminal 56 is attached to the bottom of the dimming rack housing.

FIG. 2B shows the interior of a rack according to the invention.

On the left side of the rack are a power distribution bus 30 and a signal distribution card 32.
and are placed side by side. The signal distribution card 32 is arranged vertically, and a plurality of conductor sections 34 in groups of three are provided at intervals over the entire length of the signal distribution card 32. These conductor portions serve as sliding contacts that make electrical contact with the plug-in sockets on the dimming circuit board mounted on the rack. The socket slides each circuit board into contact with the conductor section 34 and power distribution bus 30 and engages the bus 30 and signal distribution card 32 with the plug-in base when each circuit board is installed in its respective rack. A row of emergency switches 33 are mounted on the signal distribution card 32 to provide a bypass mode of operation to maintain each dimmer circuit board on or off in the event of a control panel or control circuit board failure. There is.

The power distribution bus 30 and the signal distribution card 32 are arranged vertically adjacent to each other. The power distribution busbar 30 is a continuously formed conductive member that engages a groove-shaped socket provided on the rear of the dimmer circuit board. The overhang 36 is integrally formed with the power distribution bus 30 and extends from the power distribution bus 30 at a right angle at the rear of the signal distribution card. One or more connection terminals 38 are attached to the overhang 36. A power cable is connected to the connection terminal 38 to send human power to the rack.

FIG. 2C is a partial perspective view of the side opposite the power distribution bus 30 and signal distribution card 32 side. As shown,
A plate-shaped contact 40 is integrally molded on the load connection terminal 37 . The load connection terminal 37 is attached by being fitted into the base holder 58 that constitutes the shelf portion 78 . The contacts 40 are spaced apart from the side wall of the board holder so that the contacts can engage groove-shaped sockets in the circuit board on the opposite side of the dimmer circuit board from the contacts with the signal distribution card and power distribution busbar. It is provided. The load connection terminal 37 is provided with a socket 44 and a tightening screw 46. Each electrical wire leading from the dimming rack to an incandescent lamp or other load is inserted into a socket 44 and tightened with a tightening screw 46. Each wire extends to a light or lighting device operated by a separate dimmer circuit board. A return electric wire 49 returning from a lamp load to be operated is connected to a non-polar terminal block 50 provided adjacent to the load connection terminal 37 and having a similar socket and tightening screw structure. As shown in Figure 2C,
The non-polar terminal block 50 is a continuous rectangular member in which a plurality of sockets 51 are formed. The electric wire inserted into the socket 51 is tightened and crimped with a tightening screw 52 attached to the threaded socket. The non-polar terminal block 50 is connected to the non-polar side of input power via the connection terminal 54.

Each socket 51 is connected via a cable or wire 49 to the other end of the lighting load's dimmer circuit board connection, providing the lighting load's return circuit. For example, one lighting load 150 shown in FIG. 2C is connected to return wire 49 and individual wires inserted into load connection terminals 37, one each, ie, load connection wire 49a. ing. In this way, electrical connections are made from each dimming circuit board to the lighting load 150 through the contacts 40.

As described in pending U.S. patent application Ser. 32, connected to the signal distribution card, the power distribution bus and the load connection terminals through groove-shaped sockets formed in the rear of the dimmer circuit board for engagement with the power distribution bus 30 and contacts 40.

As shown in FIG. 7, which is a bottom view of one dimmer circuit board 14 engaged with the power distribution bus 30, signal distribution card 32, and contacts 40, a groove shape formed at the rear of the dimmer circuit board 14 is shown. Sockets 230, 232 and 240 mechanically engage and make electrical contact with power distribution bus 30, signal distribution card 32 and contacts 40, respectively, when dimmer circuit board 14 is inserted into its respective shelf in the rack.

A plurality of base holder 58 moldings are attached to each side of the dimming rack. Each base holder has a shelf member 78, and a pair of six pieces 60 acting as guide members are integrally molded therein. The six pieces 60 extend vertically from the surface of each board holder and engage with grooves formed in the top and bottom surfaces near each end of the exterior of the dimming circuit board. In this way,
The dimming rack board holders guide the dimming circuit boards into and out of their respective sockets, and engage and disengage electrical connection hardware provided at the rear of each board holder.

FIG. 3 shows an exploded perspective view of a light control rack according to the present invention. The rack consists of a rear frame member 66, a first extruded sidewall 72 attached to one side of the frame member 66, and a second extruded sidewall 74 attached to the other side of the frame member 66. The dimmer circuit board holder 58 is
It is a sliding fit on the inside of the side walls 72,74. For example, the 8th
The figure shows one dimmer circuit board 14, looking toward the housing 12, engaged with the board holders 58 on the first and second side walls 72,74 of the housing 12. Six pieces 60 are fitted into respective grooves 160 formed on the upper and lower surfaces near each end of the dimming circuit board 14.

4, which is a cross-sectional view taken along line 4--4 of FIG. 3, the signal distribution card 32 and power distribution bus 30 are shown in further detail.

As shown, the signal distribution card 32 is arranged parallel to the power distribution bus 30 at a distance from the power distribution bus 30 by an insulating spacer 90 .

Furthermore, as shown in the figure, the overhanging portion 36 extending from the power distribution bus 30 fixes the connection terminal 38 and determines the position of the socket 44, and a tightening screw 46 is screwed into the connection terminal 38.

As described above, on one side of the housing there is a load connection terminal 37 and a non-polar terminal block 50 for connecting to the lighting load and then to the non-polar terminals of the power supply to form an electrical circuit.
is installed. Details of these features of the invention are shown in FIG. 5, which is a cross-sectional view taken along line 5--5 of FIG. FIG. 5 shows a state in which one of the contacts 40 on one of the load connection terminals 37 is fitted into a predetermined position of the base holder 58.

The load connection terminal 37 is also provided with a socket 44 and a tightening screw 46, through which a contact 40 is connected to a wire connecting an incandescent lamp or other lighting device controlled by the dimmer circuit board to the dimmer circuit board. be done. As shown, the non-polar terminal block 50 is located behind the load connection terminal 37,
This non-polar terminal block is provided with a socket 51 and a tightening screw 52.

An important feature of the invention is that one dimming rack can be conveniently connected to an adjacent rack via a busbar. This is shown in Figure 6, where two dimming racks 1
14.116 is shown. The physiognomic power bus 94 is
Shown on the left side of rack 114 with B-phase power bus 96 and C-phase power bus 98. The horizontal generatrix 122 is
It extends from the terminal on the power bus 94, preferably via a fuse member such as an amplifier trap, to a connection terminal attached to the human power bus 124 on the rack 116 side. If more than two racks are required to power a load, adjacent racks can be connected by horizontal busbars as well. A non-polar bus connection 126 interconnects the non-polar terminals of each rack. B phase power bus 128
is from the power bus 96 to the B-phase power bus 1 on the rack 116 side.
It extends to 18. Similarly, the C-phase power bus 130
extends between the racks 114 and 116 to connect the power bus 98 to the power bus 120 on the rack 116 side.

Interconnections for each phase are similarly arranged horizontally from rack to rack in a dimming rack located adjacent to the first dimming rack by removing the knockout panel 17 from the side of the dimming rack housing. This is done between the terminals that are connected to each other. The structure of the present invention greatly simplifies rack-to-rack interconnections while eliminating many of the hazards previously encountered in rack-to-rack interconnections.

The inputs to the busbars that connect the racks horizontally are cable 132 for A phase and cable 13 for B phase.
4, a cable 136 is used for the C phase and a cable 138 is used for the non-polar connection of the input power supply.

[Effects of the Invention] According to the present invention, there is provided a dimmer rack in which a dimmer circuit board is mounted and shelf parts with reliable fitting guides, which are board holders that engage with the dimmer circuit board, are provided along both sides of the casing. provided. This feature allows the elimination of dividers, support rails and shelves typical of the prior art. A non-polar terminal block is located adjacent to the terminal block that contains the terminals that receive the output power from the dimmer circuit board, so the output power terminals and the non-polar terminals are juxtaposed in an easily accessible location at the rear of the rack. This configuration is convenient for wiring from the dimming rack to the lighting load and return wiring therefrom, and also makes it easy to handle.

In a preferred embodiment of the rack according to the invention, a three-phase power supply A
The racks are arranged so that phase is at the top of the rack, phase B is at the middle, and phase C is at the bottom. By separating each phase in this manner, one horizontal bus bar extends horizontally from each phase to the connection point of the same phase in another rack located on either side of the rack. Racks can be connected to each other via busbars.

The present invention also provides one emergency switch for each dimmer circuit board that can be selectively operated by the user. This emergency switch is conveniently located on the signal distribution card and can be programmed to be conditioned as either "normally closed" or "normally open." In the event of a failure of the dimming rack's control electronics or control panel, the emergency switch can be preset to provide power directly from the power source to the designated portion of the lighting load being operated, bypassing the dimming rack's control electronics. be able to supply. A dimming rack according to the invention has a current interrupting capacity greater than that currently available. Its circuitry and hardware configuration is such that it can withstand current interruptions, even at extremely high current levels, without significant damage or destruction to the dimming rack in which it is housed.

The light control rack according to the present invention has easy access to each light control circuit board mounted on the light control rack, and includes a door for holding and fixing the light control circuit board in a predetermined position within the light control rack. The light control rack is characterized by a compact structure in all aspects. Since the door only covers about 1/3 of the width of the dimmer circuit board, that is, the dimmer rack, the dimmer rack of the present invention requires a space equal to the entire width of the rack in front to open and close the door. It is now possible to install it in places that were previously impossible.

[Brief explanation of the drawing]

FIG. 1A is a front view of the light control rack according to the present invention, FIG. 1B is a side view of the light control rack shown in FIG. 1A, and FIG. 1C is a front view of the light control rack according to the present invention.
The figure is a plan view of the light control rack of FIG. 1A, FIG. 2A is a front view of the light control rack according to the present invention with the door opened and all the light control circuit boards removed, and FIG. 2B is a power bus and a front view of the light control rack according to the present invention. FIG. 2C is a detailed view of a part of the signal distribution card, FIG. 2C is a detailed view of the load connection terminal mounting part and the non-polar terminal block, and FIG. 3 is an exploded perspective view of the total assembly of the dimming rack according to the present invention with the dimming circuit board removed. Figure 4 is a sectional view taken along the line 4-4 in Figure 3, Figure 5 is a sectional view taken along the line 5-5 in Figure 3, and Figure 6 shows two dimming racks according to the present invention. A partial perspective view from the front showing the above components lined up side by side and connected to each other with busbars. Figure 7 illustrates the engagement between the power busbar, the signal distribution card, the contacts connected to the connection terminals, and the dimmer circuit board. FIG. 8 is a plan view illustrating the engagement relationship between the shelf and the dimming circuit board. 10...Dimmer rack 14...Dimmer circuit board 16
...Door 17...Knockout panel 30...
・Distribution bus 32...Signal distribution card 33...Emergency switch 35...Non-polar bus 40...Contact 44...Socket 46...Tightening screw 58
...Base holder 60...6 pieces 94.96.98
...Three-phase power bus 150...Lighting load Fig. 1C Fig. 1A Fig. 1B

Claims (17)

[Claims] (1) A rack for supporting a plurality of dimming circuit boards, which includes a vertically long casing, a plurality of board holders for vertically stacking and mounting a plurality of dimmer circuit boards, and a casing. a first electrical connection member that is incorporated in a first side portion and performs the delivery of control signals; and a first electrical connection member that is incorporated in a position adjacent to the first electrical connection member on the first side portion of the casing and that is connected to the dimming circuit board. a second electrical connection member that receives and receives controlled input power; and a second electrical connection member that receives output power from a dimming circuit board provided on the casing opposite to the first side, and directs the power away from the dimming rack. and a third electrical connection member for transmitting power to a lighting load installed at a location and under control, and the first, second and third electrical connection members are connected to each of the dimmer circuit boards in a plug-in manner. A dimming rack that can be mounted and electrically connected. (2) A fourth electrical connection member, which is an electrically non-polar terminal, is incorporated at the rear of the opposite side of the casing, and this fourth electrical connection member receives electrical connection to control lighting load and dimming. The light control rack according to claim 1, wherein a power circuit is formed between the light control rack and the circuit board. (3) Claim 1 or 2, wherein the first electrical connection member has at least one power distribution bus whose longitudinal direction is in the vertical direction, and a member that connects this bus to an input power source. The dimming rack described in (2). (4) Each of the base holders has a shelf and at least one vertical convex piece protruding perpendicularly to the surface of the shelf, and the base holder is attached to a side wall of the housing. The light control rack according to any one of claims (1) to (3). (5) Each of the board holders includes a shelf and at least one vertical convex piece, the shelf is fixed to each side wall of the housing, and the convex piece is attached to the exterior of each dimmer circuit board. The light control rack according to any one of claims 1 to 3, wherein the light control rack is provided to properly fit and engage with a formed fitting groove. (6) A pair of vertical protrusions are integrally molded on each of the shelves at separate positions, and each of the protrusions has a portion extending upward from the plane of each shelf and a portion extending downward. The light control rack according to claim 5, further comprising a protruding portion. (7) The upwardly extending portions of each pair of protrusions engage with the grooves formed on the lower side of the dimming circuit board placed on the shelf, and the downwardly extending portions of each pair of protrusions The light control rack according to claim 6, wherein the extended portion engages with a groove formed on the upper side of a light control circuit board placed on the lower shelf. (8) The second electrical connection member has a signal distribution card arranged vertically, and the card is provided with a plurality of contact groups, each of which is individually electrically connected to the dimming circuit board. Claims (1) to (7) arranged so that
A dimming rack as described in any of paragraphs. (9) The third electrical connection member has a plurality of terminals, each of which has one or more plate-shaped contacts connected to the power output contacts of each of the dimmer circuit boards, and a lighting load that supplies power. Claims (1) to (1) comprising a terminal connection member for
8) The dimming rack according to any one of items 8). (10) The light control rack according to item (9), wherein each of the plurality of terminals is fixed one by one to a plurality of base holders vertically arranged in a row. (11) The light control rack according to item (10), wherein the fourth electrical connection member is an elongated member arranged parallel to and extending perpendicularly to the plurality of vertically arranged terminals. . (12) A plurality of spaced apart sockets and a plurality of associated fastening screws are provided along the elongated member, each pair of sockets being aligned with a separate base holder. 11) The dimming rack according to item 11). (13) A plurality of on/off switches are assembled into at least one group and installed inside the housing, and each of the switches is made to correspond to each of the dimmer circuit boards, so that the electronic equipment of the dimmer rack is The light control rack according to any one of claims 1 to 12, wherein the light control circuit board can be electrically bypassed in the event of a mechanical failure. (14) A door is hinged to the first side of the front surface of the housing, and the width of the door is 50 mm larger than the width of the front opening of the housing.
% or less, the light control rack according to any one of claims (1) to (13). (15) A plurality of dimmer racks each supporting a plurality of dimmer circuit boards, each of which has a vertically elongated housing and a plurality of dimmer racks each having a vertically stacked and mounted plurality of dimmer circuit boards. a base holder; a first electrical connection member that is incorporated into a first side of the casing to exchange control signals; and a first electrical connection member that is incorporated into the first side of the casing at a position adjacent to the first electrical connection member. a second electrical connection member that receives and receives input power controlled by the dimmer circuit board; and a second electrical connection member that is provided on the housing opposite to the first side and receives output power from the dimmer circuit board, and receives the output power from the dimmer circuit board. and a third electrical connection member that transmits power to a lighting load that is installed at a position remote from the dimming rack and is controlled, and the first, second, and third electrical connection members are connected to the dimming rack. A dimming rack in which each circuit board can be mounted by plugging in and electrically connected. (16) The first electrical connection member includes at least one power distribution bus having a longitudinal direction in the vertical direction, and a member connecting this bus to an input power source. Dimmable rack as described. (17) According to claim (15), wherein the first electrical connection member is comprised of three elongated power distribution busbars arranged vertically and a member for separately connecting each busbar to each phase of a three-phase input power source. Dimmable rack as described.